881 resultados para Demand forecast


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Conventional (CONV) neuromuscular electrical stimulation (NMES) (i.e., short pulse duration, low frequencies) induces a higher energetic response as compared to voluntary contractions (VOL). In contrast, wide-pulse, high-frequency (WPHF) NMES might elicit-at least in some subjects (i.e., responders)-a different motor unit recruitment compared to CONV that resembles the physiological muscle activation pattern of VOL. We therefore hypothesized that for these responder subjects, the metabolic demand of WPHF would be lower than CONV and comparable to VOL. 18 healthy subjects performed isometric plantar flexions at 10% of their maximal voluntary contraction force for CONV (25 Hz, 0.05 ms), WPHF (100 Hz, 1 ms) and VOL protocols. For each protocol, force time integral (FTI) was quantified and subjects were classified as responders and non-responders to WPHF based on k-means clustering analysis. Furthermore, a fatigue index based on FTI loss at the end of each protocol compared with the beginning of the protocol was calculated. Phosphocreatine depletion (ΔPCr) was assessed using 31P magnetic resonance spectroscopy. Responders developed four times higher FTI's during WPHF (99 ± 37 ×103 N.s) than non-responders (26 ± 12 ×103 N.s). For both responders and non-responders, CONV was metabolically more demanding than VOL when ΔPCr was expressed relative to the FTI. Only for the responder group, the ∆PCr/FTI ratio of WPHF (0.74 ± 0.19 M/N.s) was significantly lower compared to CONV (1.48 ± 0.46 M/N.s) but similar to VOL (0.65 ± 0.21 M/N.s). Moreover, the fatigue index was not different between WPHF (-16%) and CONV (-25%) for the responders. WPHF could therefore be considered as the less demanding NMES modality-at least in this subgroup of subjects-by possibly exhibiting a muscle activation pattern similar to VOL contractions.

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There is a lack of studies on tourism demand in Catalonia. To fill the gap, this paper focuses on detecting the macroeconomic factors that determine tourism demand in Catalonia. We also analyse the relation between these factors and tourism demand. Despite the strong seasonal component and the outliers in the time series of some countries, overnight stays give a better indication of tourism demand in Catalonia than the number of tourists. The degree of linear association between the macroeconomic variables and tourism demand is also higher when using quarterly rather than monthly data. Finally, there are notable differences between the results obtained for the different countries analysed. These results indicate that the best way to model tourism demand in Catalonia is to specify a quarterly model of overnight stays, differentiating between an aggregate demand model for the total number of tourists and specific models for each of the countries analysed.

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Improving educational quality is an important public policy goal. However, its success requires identifying factors associated with student achievement. At the core of these proposals lies the principle that increased public school quality can make school system more efficient, resulting in correspondingly stronger performance by students. Nevertheless, the public educational system is not devoid of competition which arises, among other factors, through the efficiency of management and the geographical location of schools. Moreover, families in Spain appear to choose a school on the grounds of location. In this environment, the objective of this paper is to analyze whether geographical space has an impact on the relationship between the level of technical quality of public schools (measured by the efficiency score) and the school demand index. To do this, an empirical application is performed on a sample of 1,695 public schools in the region of Catalonia (Spain). This application shows the effects of spatial autocorrelation on the estimation of the parameters and how these problems are addressed through spatial econometrics models. The results confirm that space has a moderating effect on the relationship between efficiency and school demand, although only in urban municipalities.

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This study considered the current situation of biofuels markets in Finland. The fact that industry consumes more than half of the total primary energy, widely applied combined heat and power production and a high share of solid biomass fuels in the total energy consumption are specific to the Finnish energy system. Wood is the most important source of bioenergy in Finland, representing 21% of the total energy consumption in 2006. Almost 80% of the wood-based energy is recovered from industrial by-products and residues. Finland has commitment itself to maintaining its greenhouse gas emissions at the 1990 level, at the highest, during the period 2008–2012. The energy and climate policy carried out in recent years has been based on the National Energy and Climate introduced in 2005. The Finnish energy policy aims to achieve the target, and a variety of measures are taken to promote the use of renewable energy sources and especially wood fuels. In 2007, the government started to prepare a new long-term (up to the year 2050) climate and energy strategy that will meet EU’s new targets for the reduction of green house gas emissions and the promotion of renewable energy sources. The new strategy will be introduced during 2008. The international biofuels trade has a substantial importance for the utilisation of bioenergy in Finland. In 2006, the total international trading of solid and liquid biofuels was approximately 64 PJ of which import was 61 PJ. Most of the import is indirect and takes place within the forest industry’s raw wood imports. In 2006, as much as 24% of wood energy was based on foreignorigin wood. Wood pellets and tall oil form the majority of export streams of biofuels. The indirect import of wood fuels increased almost 10% in 2004–2006, while the direct trade of solid and liquid biofuels has been almost constant.

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Seaports play an important part in the wellbeing of a nation. Many nations are highly dependent on foreign trade and most trade is done using sea vessels. This study is part of a larger research project, where a simulation model is required in order to create further analyses on Finnish macro logistical networks. The objective of this study is to create a system dynamic simulation model, which gives an accurate forecast for the development of demand of Finnish seaports up to 2030. The emphasis on this study is to show how it is possible to create a detailed harbor demand System Dynamic model with the help of statistical methods. The used forecasting methods were ARIMA (autoregressive integrated moving average) and regression models. The created simulation model gives a forecast with confidence intervals and allows studying different scenarios. The building process was found to be a useful one and the built model can be expanded to be more detailed. Required capacity for other parts of the Finnish logistical system could easily be included in the model.

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The main objective of this master’s thesis was to quantitatively study the reliability of market and sales forecasts of a certain company by measuring bias, precision and accuracy of these forecasts by comparing forecasts against actual values. Secondly, the differences of bias, precision and accuracy between markets were explained by various macroeconomic variables and market characteristics. Accuracy and precision of the forecasts seems to vary significantly depending on the market that is being forecasted, the variable that is being forecasted, the estimation period, the length of the estimated period, the forecast horizon and the granularity of the data. High inflation, low income level and high year-on-year market volatility seems to be related with higher annual market forecast uncertainty and high year-on-year sales volatility with higher sales forecast uncertainty. When quarterly market size is forecasted, correlation between macroeconomic variables and forecast errors reduces. Uncertainty of the sales forecasts cannot be explained with macroeconomic variables. Longer forecasts are more uncertain, shorter estimated period leads to higher uncertainty, and usually more recent market forecasts are less uncertain. Sales forecasts seem to be more uncertain than market forecasts, because they incorporate both market size and market share risks. When lead time is more than one year, forecast risk seems to grow as a function of root forecast horizon. When lead time is less than year, sequential error terms are typically correlated, and therefore forecast errors are trending or mean-reverting. The bias of forecasts seems to change in cycles, and therefore the future forecasts cannot be systematically adjusted with it. The MASE cannot be used to measure whether the forecast can anticipate year-on-year volatility. Instead, we constructed a new relative accuracy measure to cope with this particular situation.

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The Gulf of Finland is said to be one of the densest operated sea areas in the world. It is a shallow and economically vulnerable sea area with dense passenger and cargo traffic of which petroleum transports have a share of over 50 %. The winter conditions add to the risks of maritime traffic in the Gulf of Finland. It is widely believed that the growth of maritime transportation will continue also in the future. The Gulf of Finland is surrounded by three very different national economies with, different maritime transportation structures. Finland is a country of high GDP/per capita with a diversified economic structure. The number of ports is large and the maritime transportation consists of many types of cargoes: raw materials, industrial products, consumer goods, coal and petroleum products, and the Russian transit traffic of e.g. new cars and consumer goods. Russia is a large country with huge growth potential; in recent years, the expansion of petroleum exports has lead to a strong economic growth, which is also apparent in the growth of maritime transports. Russia has been expanding its port activities in the Gulf of Finland and it is officially aiming to transport its own imports and exports through the Russian ports in the future; now they are being transported to great extend through the Finnish, Estonian and other Baltic ports. Russia has five ports in the Gulf of Finland. Estonia has also experienced fast economic growth, but the growth has been slowing down already during the past couples of years. The size of its economy is small compared to Russia, which means the transported tonnes cannot be very massive. However, relatively large amounts of the Russian petroleum exports have been transported through the Estonian ports. The future of the Russian transit traffic in Estonia looks nevertheless uncertain and it remains to be seen how it will develop and if Estonia is able to find replacing cargoes if the Russian transit traffic will come to an end in the Estonian ports. Estonia’s own import and export consists of forestry products, metals or other raw materials and consumer goods. Estonia has many ports on the shores of the Gulf of Finland, but the port of Tallinn dominates the cargo volumes. In 2007, 263 M tonnes of cargoes were transported in the maritime traffic in the Gulf of Finland, of which the share of petroleum products was 56 %. 23 % of the cargoes were loaded or unloaded in the Finnish ports, 60 % in the Russian ports and 17 % in the Estonian ports. The largest ports were Primorsk (74.2 M tonnes) St. Petersburg (59.5 M tonnes), Tallinn (35.9 M tonnes), Sköldvik (19.8 M tonnes), Vysotsk (16.5 M tonnes) and Helsinki (13.4 M) tonnes. Approximately 53 600 ship calls were made in the ports of the Gulf of Finland. The densest traffic was found in the ports of St. Petersburg (14 651 ship calls), Helsinki (11 727 ship calls) and Tallinn (10 614 ship calls) in 2007. The transportation scenarios are usually based on the assumption that the amount of transports follows the development of the economy, although also other factors influence the development of transportation, e.g. government policy, environmental aspects, and social and behavioural trends. The relationship between the development of transportation and the economy is usually analyzed in terms of the development of GDP and trade. When the GDP grows to a certain level, especially the international transports increase because countries of high GDP produce, consume and thus transport more. An effective transportation system is also a precondition for the economic development. In this study, the following factors were taken into consideration when formulating the future scenarios: maritime transportation in the Gulf of Finland 2007, economic development, development of key industries, development of infrastructure and environmental aspects in relation to maritime transportation. The basic starting points for the three alternative scenarios were: • the slow growth scenario: economic recession • the average growth scenario: economy will recover quickly from current instability • the strong growth scenario: the most optimistic views on development will realize According to the slow growth scenario, the total tonnes for the maritime transportation in the Gulf of Finland would be 322.4 M tonnes in 2015, which would mean a growth of 23 % compared to 2007. In the average growth scenario, the total tonnes were estimated to be 431.6 M tonnes – a growth of 64 %, and in the strong growth scenario 507.2 M tonnes – a growth of 93%. These tonnes were further divided into petroleum products and other cargoes by country, into export, import and domestic traffic by country, and between the ports. For petroleum products, the share of crude oil and oil products was estimated and the number of tanker calls in 2015 was calculated for each scenario. However, the future development of maritime transportation in the GoF is dependent on so many societal and economic variables that it is not realistic to predict one exact point estimate value for the cargo tonnes for a certain scenario. Plenty of uncertainty is related both to the degree in which the scenario will come true as well as to the cause-effect relations between the different variables. For these reasons, probability distributions for each scenario were formulated by an expert group. As a result, a range for the total tonnes of each scenario was formulated and they are as follows: the slow growth scenario: 280.8 – 363 M tonnes (expectation value 322.4 M tonnes)

  • the average growth scenario: 404.1 – 465.1 M tonnes (expectation value 431.6 M tonnes)
  • the strong growth scenario: 445.4 – 575.4 M tonnes (expectation value 507.2 M tonnes) Three alternatives scenarios were evaluated to realize most likely with the following probability distribution:
  • the slow growth scenario: 35 %
  • the average growth scenario: 50 %
  • the strong growth scenario: 15 %. In other words, expert group evaluated the average growth scenario to be the most likely to realize, second likely was the slow growth scenario, and the strong growth scenario was evaluated to be the most unlikely to realize. In sum, it can be stated that the development of maritime transportation in the Gulf of Finland is dominated by the development of Russia, because Russia dominates the cargo volumes. Maritime transportation in Finland is expected to be more stable and, in any case, such a growth potential cannot be seen in Finland. The development of maritime transportation in Estonia is rather challenging to forecast at the moment but, on the other hand, the transported tonnes in the Estonian ports are relatively small. The shares of export and import of the maritime transportation are not expected to change radically in the reference period. Petroleum products will dominate the transports also in the future and the share of oil products will probably increase compared to the share of crude oil. In regard to the other cargoes, the transports of raw materials and bulk goods will probably be replaced to some extend by cargoes of high-value, which adds especially to the container transports. But in overall, substantial changes are not expected in the commodity groups transported by sea. The growth potential of the ports concentrates on the Russian ports, especially Primorsk and Ust-Luga, if investments will come true as planned. It is likely that the larger ports do better in the competition than the small ones due to the economies of scale and to the concentration of cargo flows. The average ship sizes will probably grow, but the growth potential is rather limited because of geographical conditions and of the maritime transportation structure in the Gulf of Finland. Climate change and other environmental aspects are becoming more central e.g. in transportation politics. These issues can affect the maritime transportation in the Gulf of Finland through, for instance, strict environmental requirements concerning the emissions from shipping, or the port investments. If environmental requirements raise costs, it can affect the demand of transportation. In the near future, the development of the maritime transportation in the Gulf of Finland is mainly dependent on the current economic instability. If it will lead to a longer lasting recession, the growth of the transported tonnes will slow down. But if the instability does not last long, it can be expected that the economic growth will continue and along with it also the growth of transported tonnes.

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    Hoy día, todo el mundo tiene un ojo puesto en el Mercado Eléctrico en nuestro país. No existe duda alguna sobre la importancia que tiene el comportamiento de la demanda eléctrica. Una de las peculiaridades de la electricidad que producimos, es que hoy por hoy, no existen aún métodos lo suficientemente efectivos para almacenarla, al menos en grandes cantidades. Por consiguiente, la cantidad demandada y la ofertada/producida deben casar de manera casi perfecta. Debido a estas razones, es bastante interesante tratar de predecir el comportamiento futuro de la demanda, estudiando una posible tendencia y/o estacionalidad. Profundizando más en los datos históricos de las demandas; es relativamente sencillo descubrir la gran influencia que la temperatura ambiente, laboralidad o la actividad económica tienen sobre la respuesta de la demanda. Una vez teniendo todo esto claro, podemos decidir cuál es el mejor método para aplicarlo en este tipo de series temporales. Para este fin, los métodos de análisis más comunes han sido presentados y explicados, poniendo de relieve sus principales características, así como sus aplicaciones. Los métodos en los que se ha centrado este proyecto son en los modelos de alisado y medias móviles. Por último, se ha buscado una relación entre la demanda eléctrica peninsular y el precio final que pagamos por la luz.

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    Budget forecasts have become increasingly important as a tool of fiscal management to influence expectations of bond markets and the public at large. The inherent difficulty in projecting macroeconomic variables – together with political bias – thwart the accuracy of budget forecasts. We improve accuracy by combining the forecasts of both private and public agencies for Italy over the period 1993-2012. A weighted combined forecast of the deficit/ ratio is superior to any single forecast. Deficits are hard to predict due to shifting economic conditions and political events. We test and compare predictive accuracy over time and although a weighted combined forecast is robust to breaks, there is no significant improvement over a simple RW model.

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    Budget forecasts have become increasingly important as a tool of fiscal management to influence expectations of bond markets and the public at large. The inherent difficulty in projecting macroeconomic variables – together with political bias – thwart the accuracy of budget forecasts. We improve accuracy by combining the forecasts of both private and public agencies for Italy over the period 1993-2012. A weighted combined forecast of the deficit/ ratio is superior to any single forecast. Deficits are hard to predict due to shifting economic conditions and political events. We test and compare predictive accuracy over time and although a weighted combined forecast is robust to breaks, there is no significant improvement over a simple RW model.

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    The master’s thesis focused on implementing a sales and operations planning process. The main objectives were to create planning methods and tools for the implementation. The ultimate goal of the process, beyond this master’s thesis, is to balance the supply of products with customer demand, with optimized profitability. The theoretical part focused on giving a thorough view on the sales and operations planning process. The basis for a monthly planning cycle was identified. Methods, tools, and metrics for demand forecasting and operations planning were also introduced. Based on the theoretical part, a method for forecasting, a forecast spreadsheet, and a forecast accuracy metric were designed. A spreadsheet tool and methods were also designed for the monthly planning of production volumes, capacity, and inventory. The implementation progress was reviewed for two product families for three months. The sales and operations planning process was able to successfully identify a demand peak for the product families. Suggestions for the future of sales and operations planning were also made.

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    Russia has been one of the fastest developing economic areas in the world. Based on the GDP, the Russian economy grew evenly since the crisis in 1998 up till 2008. The growth in the gross domestic product has annually been some 5–10%. In 2007, the growth reached 8.1%, which is the highest figure after the 10% growth in 2000. Due to the growth of the economy and wage levels, purchasing power and consumption have been strongly increasing. The growing consumption has especially increased the imports of durables, such as passenger cars, domestic appliances and electronics. The Russian ports and infrastructure have not been able to satisfy the growing needs of exports and imports, which is why quite a large share of Russian foreign trade is going through third countries as transit transports. Finnish ports play a major role in transit transports to and from Russia. About 15% of the total value of Russian imports was transported through Finland in 2008. The economic recession that started in autumn 2008 and continues to date has had an impact on the economic development of Russia. The export income has decreased, mainly due to the reduced world market prices of energy products (oil and gas) and raw minerals. Investments have been postponed, getting credit is more difficult than before, and the ruble has weakened in relation to the euro and the dollar. The imports are decreasing remarkably, and are not forecast to reach the 2008 volumes even in 2012. The economic crisis is reflected in Finland's transit traffic. The volume of goods transported through Finland to and from Russia has decreased almost in the same proportion as the imports of goods to Russia. The biggest risk threatening the development of the Russian economy over long term is its dependence on export income from oil, gas, metals, minerals and forest products, as well as the trends of the world market prices of these products. Nevertheless, it is expected that the GDP of Russia will start to grow again in the forthcoming years due to the increased demand for energy products and raw minerals in the world. At the same time, it is obvious that the world market prices of these products will go up with the increasing demand. The increased income from exports will lead to a growth of imports, especially those of consumer goods, as the living standard of Russian citizens rises. The forecasts produced by the Russian Government concerning the economic development of Russia up till 2030 also indicate a shift in exported goods from raw materials to processed products, which together with energy products will become the main export goods of Russia. As a consequence, Russia may need export routes through third countries, which can be seen as an opportunity for increased transit transports through the ports of Finland. The ports competing with the ports of Finland for Russian foreign trade traffic are the Russian Baltic Sea ports and the ports of the Baltic countries. The strongest competitors are the Baltic Sea ports handling containers. On the Russian Baltic Sea, these ports include Saint Petersburg, Kaliningrad and, in the near future, the ports of Ust-Luga and possibly Vyborg. There are plans to develop Ust-Luga and Vyborg as modern container ports, which would become serious competitors to the Finnish ports. Russia is aiming to redirect as large a share as possible of foreign trade traffic to its own ports. The ports of Russia and the infrastructure associated with them are under constant development. On the other hand, the logistic capacity of Russia is not able to satisfy the continually growing needs of the Russian foreign trade. The capacity problem is emphasized by a structural incompatibility between the exports and imports in the Russian foreign trade. Russian exports can only use a small part of the containers brought in with imports. Problems are also caused by the difficult ice conditions and narrow waterways leading to the ports. It is predicted that Finland will maintain its position as a transit route for the Russian foreign trade, at least in the near future. The Russian foreign trade is increasing, and Russia will not be able to develop its ports in proportion with the increasing foreign trade. With the development of port capacity, cargo flows through the ports of Russia will grow. Structural changes in transit traffic are already visible. Firms are more and more relocating their production to Russia, for example as regards the assembly of cars and warehousing services. Simultaneously, an increasing part of transit cargoes are sent directly to Russia without unloading and reloading in Finland. New product groups have nevertheless been transported through Finland (textile products and tools), replacing the lost cargos. The global recession that started in autumn 2008 has influenced the volume of Russian imports and, consequently, the transit volumes of Finland, but the recession is not expected to be of long duration, and will thus only have a short-term impact on transit volumes. The Finnish infrastructure and services offered by the logistic chain should also be ready to react to the changes in imported product groups as well as to the change in Russian export products in the future. If the development plans of the Russian economy are realized, export products will be more refined, and the share of energy and raw material products will decrease. The other notable factor to be taken into consideration is the extremely fast-changing business environment in Russia. Operators in the logistic chain should be flexible enough to adapt to all kinds of changes to capitalise on business opportunities offered by the Russian foreign trade for the companies and for the transit volumes of Finnish ports, also in the future.

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    Demand forecasting is one of the fundamental managerial tasks. Most companies do not know their future demands, so they have to make plans based on demand forecasts. The literature offers many methods and approaches for producing forecasts. When selecting the forecasting approach, companies need to estimate the benefits provided by particular methods, as well as the resources that applying the methods call for. Former literature points out that even though many forecasting methods are available, selecting a suitable approach and implementing and managing it is a complex cross-functional matter. However, research that focuses on the managerial side of forecasting is relatively rare. This thesis explores the managerial problems that are involved when demand forecasting methods are applied in a context where a company produces products for other manufacturing companies. Industrial companies have some characteristics that differ from consumer companies, e.g. typically a lower number of customers and closer relationships with customers than in consumer companies. The research questions of this thesis are: 1. What kind of challenges are there in organizing an adequate forecasting process in the industrial context? 2. What kind of tools of analysis can be utilized to support the improvement of the forecasting process? The main methodological approach in this study is design science, where the main objective is to develop tentative solutions to real-life problems. The research data has been collected from two organizations. Managerial problems in organizing demand forecasting can be found in four interlinked areas: 1. defining the operational environment for forecasting, 2. defining the forecasting methods, 3. defining the organizational responsibilities, and 4. defining the forecasting performance measurement process. In all these areas, examples of managerial problems are described, and approaches for mitigating these problems are outlined.